There are a variety of systems that allow a computer to be accessed remotely. One kind of system provides remote access to a “desktop” environment, in which a user has access to a typical personal computer configuration, with the ability to run multiple applications and access storage. It is common in a desktop environment to have different applications displayed in different display areas, which may overlap on a display.
When the display for a desktop is rendered, and then displayed remotely, existing technologies send the image data for changed regions in the display over the network. In particular, these changed regions are called “dirty” regions, and are sent across the network.
There are cases in which updates to the desktop result in regions moving across the desktop. Such region movement typically happens as a result of window scrolls or window moves. However, if the remote updating method involves sending data for areas that have changed, an entire scrolled or moved window will be sent.